At the end of 1Q 2013, there was just a 2.6-month supply of houses on the market — down 20 percent from 1Q 2012 and the lowest in more than two decades. The average time on the market was only about 65 days in 1Q 2013. That’s down from almost three months in 1Q 2009.

“Sales volume keeps exceeding the listings,” said James Gaines, an economist with the Real Estate Center at Texas A&M University. “There is no way we should be having the sales volumes we are seeing given the number of listings we have.”